Fish and Shellfish: What You Need to Know About Mercury, Pregnancy, and Fertility

Fish and seafood get a bad rap when it comes to preconception and prenatal nutrition. While it's true that some kinds are high in mercury, it's equally true that fish and shellfish are bursting at the seams with health benefits.

Health Benefits of Fish and Shellfish

Fish and shellfish have omega 3s for heart health and beautiful skin, B vitamins for ample energy and healthy blood cells, and protein for muscle development and to keep us full and satisfied longer. Those all sound like good things to me. And that's not all. Each kind has different nutrients. Some are good or excellent sources of zinc for wound healing and healthy hair, vitamin D for strong bones and a healthy immune system, and selenium for thyroid and reproductive health.

Dangers of Too Much Mercury

With all of that being said, mercury toxicity is a very real concern. Mercury is a neurotoxin, meaning it can harm our nervous system. Not exactly a good thing, especially during early development. High levels have also been linked to an increased risk of infertility.

The key to reaping the benefits without the icky drawbacks is to eat the ones that have low and moderate amounts of mercury. This is especially true for women of child bearing age, pregnant women, breastfeeding women, and young children. People in these groups should steer completely clear of fish and seafood that have high levels of mercury.

Don't forget, pregnant women and young children should also avoid under cooked or raw fish and shellfish. Sorry, no sashimi for you.

Mercury Levels of Different Fish and Shellfish

Low

Feel free to eat these 2 or more times per week

  • American Shad
  • Anchovies
  • Atlantic Croaker
  • Atlantic Haddock
  • Butterfish
  • Catfish
  • Clam
  • Crab
  • Crawfish
  • North Atlantic Mackerel (Chub)
  • Flounder
  • Freshwater Trout
  • Hake
  • Herring
  • Mullet
  • Oyster
  • Ocean Perch
  • Pacific Sole
  • Plaice
  • Pollock
  • Canned or fresh salmon
  • Sardines
  • Scallops
  • Shrimp
  • Squid
  • Tilapia
  • Whitefish
  • Whiting

High

Only eat these once every two weeks or so; definitely no more 3 times per month

  • Bluefish
  • Canned Albacore or White Tuna
  • Chilean Sea Bass
  • Grouper
  • Gulf Mackerel
  • Spanish Mackerel
  • Yellowfin Tuna

Moderate

Limit these to once or twice a week

  • Alaskan Cod
  • Atlantic Halibut
  • Black or Striped Bass
  • Canned chunk light tuna
  • Carp
  • Croaker
  • Freshwater Perch
  • Jacksmelt (Silverside)
  • Lobster
  • Mahi Mahi
  • Monkfish
  • Pacific Halibut
  • Sablefish
  • Skate
  • Skipjack Tuna
  • Snapper
  • Weakfish (Sea Trout)

Super High

Just don't ...

  • Ahi Tuna
  • Bigeye Tuna
  • King Mackerel
  • Marlin
  • Orange Roughy
  • Shark
  • Swordfish
  • Tilefish